import java.util.Scanner;
public class ScoreAverage{
   public static void main(String[] args){
      Scanner scanner=new Scanner(System.in);
	  int score=0;
	  int sum=0;
	  int count=-1;
	  while(score!=-1){
	     count++;
		 sum+=score;
		 System.out.print("when you enter -1, the program will be ended:");
		 score=scanner.nextInt();
	  }
	  System.out.println("Average:"+(double)sum/count);
   }

}